Hi Hans,
On Mon, Apr 9, 2018 at 11:21 PM Hans Verkuil <hverkuil@xxxxxxxxx> wrote:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> Implement the MEDIA_REQUEST_IOC_QUEUE and MEDIA_REQUEST_IOC_REINIT
> ioctls.
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> drivers/media/media-request.c | 80
+++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 78 insertions(+), 2 deletions(-)
> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> index dffc290e4ada..27739ff7cb09 100644
> --- a/drivers/media/media-request.c
> +++ b/drivers/media/media-request.c
> @@ -118,10 +118,86 @@ static unsigned int media_request_poll(struct file
*filp,
> return 0;
> }
> +static long media_request_ioctl_queue(struct media_request *req)
> +{
> + struct media_device *mdev = req->mdev;
> + unsigned long flags;
> + int ret = 0;
> +
> + dev_dbg(mdev->dev, "request: queue %s\n", req->debug_str);
> +
> + spin_lock_irqsave(&req->lock, flags);
> + if (req->state != MEDIA_REQUEST_STATE_IDLE) {
> + dev_dbg(mdev->dev,
> + "request: unable to queue %s, request in state
%s\n",
> + req->debug_str,
media_request_state_str(req->state));
> + spin_unlock_irqrestore(&req->lock, flags);
> + return -EINVAL;
nit: Perhaps -EBUSY? (vb2 returns -EINVAL, though, but IMHO it doesn't
really represent the real error too closely.)
> + }
> + req->state = MEDIA_REQUEST_STATE_QUEUEING;
> +
> + spin_unlock_irqrestore(&req->lock, flags);
> +
> + /*
> + * Ensure the request that is validated will be the one that gets
queued
> + * next by serialising the queueing process.
> + */
> + mutex_lock(&mdev->req_queue_mutex);
> +
> + ret = mdev->ops->req_queue(req);
> + spin_lock_irqsave(&req->lock, flags);
> + req->state = ret ? MEDIA_REQUEST_STATE_IDLE :
MEDIA_REQUEST_STATE_QUEUED;
> + spin_unlock_irqrestore(&req->lock, flags);
> + mutex_unlock(&mdev->req_queue_mutex);
> +
> + if (ret) {
> + dev_dbg(mdev->dev, "request: can't queue %s (%d)\n",
> + req->debug_str, ret);
> + } else {
> + media_request_get(req);
I'm not convinced that this is the right place to take a reference. IMHO
whoever saves a pointer to the request in its own internal data (the
->req_queue() callback?), should also grab a reference before doing so. Not
a strong objection, though, if we clearly document this, so that whoever
implements ->req_queue() callback can do the right thing.
> + }
> +
> + return ret;
> +}
> +
> +static long media_request_ioctl_reinit(struct media_request *req)
> +{
> + struct media_device *mdev = req->mdev;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&req->lock, flags);
> + if (req->state != MEDIA_REQUEST_STATE_IDLE &&
> + req->state != MEDIA_REQUEST_STATE_COMPLETE) {
> + dev_dbg(mdev->dev,
> + "request: %s not in idle or complete state,
cannot reinit\n",
> + req->debug_str);
> + spin_unlock_irqrestore(&req->lock, flags);
> + return -EINVAL;
nit: Perhaps -EBUSY? (Again vb2 would return -EINVAL...)
Best regards,
Tomasz
